An obvious form of Wish-Fulfillment fantasy, this trope allows the protagonist (who is almost always a self-insert or Audience Surrogate, and thus almost Always Male) to enjoy the privilege of a number of servants who are also deeply in love with him/her. The exact nature of the servitude can vary, whether it be legal ownership, Indentured Servitude, a Magically Binding Contract, a pledge of eternal fealty, Mind Manipulation, programming or some other form of Unequal Pairing that makes one person forced or obligated to obey the other.
Due to slavery being seen as an unforgivable violation of a person's consent, agency and freedom; and sex with a slave being legally a form of rape, this trope is one that many writers shy away from. However, the trope has exploded in popularity within Light Novels, becoming one of the most common forms of Love Interest for the Stock Light-Novel Hero alongside the Shana Clone, Stock Light-Novel Calamity Princess and Little Sister Heroine (and these are not mutually exclusive — Mio Narase from The Testament of Sister New Devil is all four). While its initial growth can be put down to its sheer utility in an isekai Power Fantasy story (even the blandest, least charismatic protagonist can attract companions if you can just buy them), the concept would quickly become embedded enough in the genre for "is or was recently a slave" to become a popular trait in heroines regardless of context.
Usually, the relationship will be portrayed as "unproblematic", whereas the slaves are content with being owned by their beloved master and may even possess small amounts of "authority" (e.g., the owner may claim that they can be released any time they like or are allowed to speak their mind and maybe even question their orders). They may even avoid the words "slave" or "slavery" altogether, and portray the arrangement as simply "employment" or "working off a debt". In many portrayals, the owner will also be a Chaste Hero who refuses to use their servants as Sex Slaves, regardless of how much they want them to. However, none of this changes the fact that the protagonist has the option to do indecent things with their harem, and the only thing stopping them is their own self-restraint. In this trope, said self-restraint and desire not to abuse their power is often portrayed as the virtuous, heroic thing to do in opposition to simply freeing the slaves outright. Finally, the fact that they are, if not outright contributing to the upholding of slavery as an institution, at the very least tacitly endorsing it, will probably also go unremarked upon.
To be clear, this trope carries a ton of Unfortunate Implications, not helped by the fact that enslavement is historically one of the cruelest things that one person can do to another, and has been outlawed all across the world with good reason. In Japanese Media, this trope also carries high levels of Values Dissonance; in the West, subservience is typically portrayed as a weakness or gross injustice, but in the East, it is often seen as a sign of purity, selflessness, and devotion. It is also often inaccurately conflated to BDSM; the cardinal rule of BDSM play is Safe, Sane, and Consensual, so having no power over what someone tells you to do fails the first and third tenet, and any form of Mind Manipulation would also fail the second.
A Sub-Trope of Property of Love and often Beautiful Slave Girl. Also a form of Romanticized Abuse and Protagonist-Centered Morality, as the trope is usually provided justification under the logic that there's no problem if the protagonist is a Nice Guy and treats his servants well. Compare Royal Harem, when the person with the harem is a ruler or sovereign.
Contrast Exotic Extended Marriage (when a foreigner is the one with a harem to add a degree "otherness").
- DearS: Double Subverted. While the DearS are a Slave Race, Takeya initially wants nothing to do with them, and while he becomes Ren's "master", she's the only DearS to become his slave even as others are attracted to him. At the end of the manga, however, after deciding to go into space with the DearS, Takeya ends up being the only guy on a spaceship full of alien slavegirls who are all deeply in love with him and willing to start making babies with him.
- Death March to the Parallel World Rhapsody: Satou saves a trio of demihuman slaves from an abusive master, and they choose to stay with him, since there's widespread discrimination against demihumans and being the property of a kind human owner is safer for them than actually being free. Later, he is glamoured into buying a pair of human sisters as slaves because one of the sisters is highly attracted to him and was hoping he'd use her as a Sex Slave (and they're under a powerful geas that requires them to spend the rest of their lives as slaves, so they can't be freed either). Even later still, he saves nine gynoids who also pledge themselves to his service (one of whom repeatedly tries to sleep with him). Satou, however, pointedly prefers women his own (mental) age,note meaning that almost all of his slaves (whose ages range from very young to mid-teens) are too young for him. Later in the story, however, they manage to trick him into saying he will marry them if they're available in ten years or more.
- How Not to Summon a Demon Lord: When the protagonist Diablo is summoned to a fantasy world, his ring that deflects all magic reverses the slave spell that the two girls who summoned him had used and thus makes them his slaves instead of the other way around. At first, no one is happy with the arrangement and they look for ways of reversing the spell, but after Diablo shows himself to be a Nice Guy underneath his Jerkass Façade, the girls fall in love with him and actually take pride in being called his "property". He acquires more girls later (some, though not all, becoming his slaves as well).
- How to Build a Dungeon: Book of the Demon King: Ein Sof Aur is a deconstruction, being a Villain Protagonist with none of the scruples that harem protagonists usually have. About two-thirds of the women in his harem are with him voluntarily; the others are variously gaslit, brainwashed, or driven over the Despair Event Horizon. In nearly all cases, he cast a curse on them to make it impossible for them to ever act against them.
- In Another World with My Smartphone: In addition to the main heroines that act as his brides, protagonist Touya Mochizuki also eventually acquires nine artificial human gynoids which were specifically created to be sex bots for him. After imprinting him as their master, all nine robots want nothing more than to be "used" by Touya, with Cesca in particular being extremely aggressive about it. On top of this, Touya eventually becomes king of his own country and many women under his command also show an interest in being a mistress or otherwise having a romantic relationship with him.
- Infinite Dendrogram: Parodied with Rook, one of the most "protagonist-y" members of the cast, whose "Pimp" class allows him to seduce females and enhance the stats of female minions. However, he's The Beastmaster whose "harem" consists only of female monsters - he initially picked up the class because it had good synergy with the female Bond Creature that came with his character. It's heavily implied that this is Not the Intended Use of that class, which is noted to be more common with NPCs than with players. Adding to the gag is that, because Rook is a minor, the game's automatic censorship prevents him from seeing about half the content of the Pimp class quests, making it unclear if Rook even knows what a Pimp is. Later books reveal that he knew all along... but also imply that he's gay.
- Lord Marksman and Vanadis: Double Subverted in regards to Tigre and Elen; early in the story, she takes him prisoner after he fails to defeat her in battle, intending to use him as a ransom. As a prisoner, the two of them become more interested and attracted to one-another, although Elen always reminds Tigre (as well as any other girls desiring him) that he "belongs" to her. Later in the story, however, Tigre gains more and more political power to the degree that several groups and nations swear fealty to him, including Titta, his personal servant since childhood.
- The Master of Ragnarok & Blesser of Einherjar: Yuuto Suoh is summoned to another world/time and made the Patriarch of the Wolf Clan after the original Patriarch dies. As such, the members of the clan (as well as those of other clans whom the Wolf Clan conquers) take a "Chalice Oath" in which they swear fealty to him and claim to be his property. Many of these women also begin to call themselves his "daughters" or "little sisters", but nonetheless want to become his wife or one of his mistresses.
- Monster Girl Doctor: Discussed Trope between Kay, Lorna and Dr. Glenn. Kay and Lorna are the sword servants of lady Tisalia, and describe themselves as their lady's "property" under centaur tradition. When alone with Glenn, the two of them try to seduce him, knowing that their mistress is in love with him, under the logic that if successful, Glenn would have no choice but to marry Tisalia in order to take responsibility. When their attempt fails, the two are unfazed and state that they only see it as a matter of time before Glenn marries Tisalia, and since centaur law dictates that spouses share all property, then that will make them his property as well...which they are very excited about.
- No Game No Life: Downplayed Trope. Early in the series, it is revealed that any stipulations or agreements made before a game are magically-binding. This comes back to bite Stephanie, who wagers that she will do anything Sora says if he can defeat her in a game of rock-paper-scissors. His command is "Fall in love with me", which results in a very conflicted Stephanie desperately trying to fight her newfound feelings of affection for Sora. Later, Sora also defeats the Fluegel Jibril, who becomes Sora's servant; while Jibril is an amoral being with no true feelings one way or another, she is quite The Tease and has stated numerous times that she would not hesitate to sleep with Sora if he ordered her to, or simply to sate her own curiosity. Another downplayed example is Laira, a Siren who is in love with Sora simply because he doesn't reciprocate it; her obsession with being in a one-sided love means that she even desires to be mistreated by him — the more cruelly he treats her, the more she loves him.
- Overlord (2012): Ainz Ooal Gown is the supreme ruler of The Great Tomb of Nazarick, and because every resident besides himself were once videogame NPCs, they are bound to obey his will. Several female NPCs in the Tomb are also either in love with him (Albedo, Shalltear) or greatly lust after him (Solution Epsilon and Neuronist Painkill). While Ainz is a Villain Protagonist, he is A Lighter Shade of Black who is both aware of the interests of his female subjects and in fact disturbed by it. He confesses to Albedo at one point that he reset her settings to be in love with him, but she dismisses it and says that if her love doesn't bother him, then she sees no problem. Adding to the irony of the situation is the fact that Ainz is a skeletal Lich, with no sex drive nor relevant organs, which doesn't actually stop the ladies from wanting to jump his bones and (somehow) have his children.
- Downplayed in Reborn as a Space Mercenary: I Woke Up Piloting the Strongest Starship!. Hiro rescues Mimi from an attempted gang-rape, buys out her debts, and hires her as a trainee crew member to work off what she owes him. Mimi insists on sleeping with him that night; he's initially reluctant but she succeeds in seducing him. A similar situation plays out later with Elma, an experienced mercenary pilot who incurs massive fines in an accidental collision. It's not until way later that either girl bothers to explain to him that, by local custom, if a male starship captain hires a female crew member, she's consenting to be his doxy in addition to her other duties; they mistakenly assumed he already knew. At first, he actively refuses to add additional girls to his harem afterwards: he's not attracted to Serena Holz despite or perhaps because of her yandereness to him, and Christina Daleinwald is way too young for him even if he did want her, though, in Chris's case, the bigger issue is that her grandfather, a powerful noble, actively opposes her pursuit of him; its made clear that the only reason he didn't lay a hand on her when she offered herself to him is because of this. He does later play the trope straighter and cease defying it when he brings Mei, a "maidroid" (a gynoid dressed as a maid) onto his ship and into his harem, and attempts to do the same with Dr. Shouko (she turns him down, being Married to the Job). So he isn't so much defying the trope as being very selective in who he brings into his "harem", as they are also his crew members, and he seeks those who will help him further his goals. Notably, neither Christina nor Serena have given up pursuing him.
- Redo of Healer: The protagonist Keyaru gains healing abilities in his adolescence but quickly finds out that they come with horrific drawbacks. The sadistic Princess Flare thus takes him prisoner, makes him addicted to drugs, and has him repeatedly raped by several members of both genders (due to sex making others' abilities stronger). After he eventually becomes immune to drugs, he rewinds time to the beginning and starts acquiring new abilities, eventually learning how to erase memories and other forms of Mind Manipulation. Afterwards, Flare becomes "Freya", a much kinder and nicer person who falls deeply in love with Keyaru. Later, he also purchases a beast girl named Setsuna, who also becomes fiercely devoted to him. He later also brainwashes Flare's younger sister Norn (who is even worse than Flare), and she becomes "Ellen", who also eagerly has sex with Keyaru. (On the moral side of the spectrum, it should be noted that Keyaru is unashamedly a Villain Protagonist and a Noble Demon at best, who is only A Lighter Shade of Black in comparison with most of his enemies, who tend to be truly appalling Hate Sinks.)
- The Rising of the Shield Hero: The series responsible for popularising this trope in Light Novels, though it differs from many later examples in that the protagonist buying slaves is portrayed as an Anti-Hero trait and something he only considers as a last resort.
- Early into the story, the hero Naofumi purchases a beast child named Raphtalia to be his combat slave. He does this because his shield's Crippling Overspecialization forces him to rely on trustworthy companions in battle... but his first companion publicly framed him for rape, both ruining his reputation and sending him Maddened Into Misanthropy. He only feels safe around someone bound by a Magically Binding Contract not to betray him (and in the novel, claims to find it outright cathartic to have "someone like her" under his power). However, after being cured of an illness, being well taken care of, and taught to become a stronger person, Raphtalia quickly falls in love with Naofumi and happily continues to be his slave. At one point Raphtalia's slave contract is broken, sending Naofumi into a Heroic BSoD, only for her to restore it herself as a show of her faith in him.
- Naofumi also later gains several other companions and slaves as well, some of whom also fall in love with him, though his general Obliviousness keeps him from taking advantage of the situation for the vast majority of the story. Naofumi's lingering trust issues mean that he refuses to accept travelling companions unless they accept at least a temporary slave contract. This also has a practical benefit, in that being bound to Naofumi through magic allows them to grow in strength as he does.
- Samurai Girls: Defied trope via Insistent Terminology. The Central Theme of the series is that the heroes argue that the relationship between samurai and their general is not slavery — that even if a samurai is sworn to protect and obey their general, this comes from a place of mutual respect, trust and bonding rather than servitude. The villains, however, are particularly those who see no difference, and use samurai as disposable tools, fodder and even sex slaves. However, this debate coincides with the fact that the master samurai introduced are all women and most serve the protagonist, Muneakira Yagyu.
- Slave Harem in the Labyrinth of the Other World is pretty much Exactly What It Says on the Tin - a harem of the Sex Slave variety. Michio also happens to be a Harem Seeker to boot. Fortunately for the girls, Michio goes so far above and beyond his duties as the master of his slave harem that they consider themselves to be living in the lap of luxury, and try to make Michio as happy as they can. It also helps that they have final say in whether Michio can have sex with them or not.
- The Testament of Sister New Devil: Basara establishes a master-servant contract with several women (in the original case with Mio, he was supposed to have been the subservient partner, but Maria got part of the ritual backwards), with erotic and sexual contact explicitly essential to it. The contract prevents a servant from acting or even thinking of disobeying their master's wishes, as it will immediately make them Overcome with Desire to a crippling degree and can only be freed from such desire by their master. It's also demonstrated that other conditions can be met to "punish" slaves, such as teleporting them to another dimension. To highlight just how easily-abusable this system is, the Big Bad Zolgia and several of his followers/admirers take joy in using the contract to make women their Sex Slaves, and especially taking other men's slaves and using the agony and discomfort of the contract to break their minds until they enter a vegetative state and can be sexually abused at will.
- TSUKIMICHI -Moonlit Fantasy-: Makoto quickly winds up with Tomoe and Mio as servants, with both women expressing a willingness (in Mio's case, an eagerness) to "service" him sexually. In Tomoe's case, she originally attempted to form a 50-50 contract with Makoto that would make them equal partners, but found it impossible to do because he had such an absurd amount of mana, and she eventually settled for 80-20, which gives her almost no power in the deal. Mio, on the other hand, gleefully accepts a position as Makoto's slave. At first, Makoto chooses to abstain from pursuing anything sexual with Tomoe or Mio on he basis that it would be cruel if he ever returned to Earth, but after deciding to stay on the Goddess's world, he becomes so sexually aggressive that Tomoe and Mio find that they can't keep up with his stamina. He also later gains a male servant (Shiki) and another female (Tamaki).
- World's End Harem: Fantasia: Once Arc gains the power of Macht, any woman who consumes his blood becomes unable to live without consuming his fluids (sweat, saliva, blood, and semen all work equally well). Lati took it upon herself to kidnap the first couple of women and infuse them without even Arc's consent, to demonstrate how the power worked. After incidents with Wenna and Cassia,note Arc has a Heel Realization about the whole thing and starts making sure that anyone else he infuses with Macht is fully informed of the consequences and benefits beforehand and explicitly consents.
- Paladin of Shadows: By the third book in series, Mike has become an the head of a Keldara clan, which gives him prima nocta privileges. (It's implied that several women in the tribe have no problem with this.) Also, when their mission sends them against sex slavers and human traffickers, the "good guys" have no qualms about "liberating" women, then paying a wad of cash for them to service Mike and his team.
- As the famous LiveJournal review points out, Mike employs sex workers for a lot of tasks: as translators, infiltrators, assasins, etc, but he always winds up acquiring an entire harem of barely-legal women for sex.
- The Tough Guide to Fantasyland: When it talks about "Slaves, Female" of the Royal Harem type:
"Beautiful young women. You will find these in droves in the FANATIC CALIPHATES and sometimes in the PALACES of bad KINGS. Their duties are light and pleasant and are: looking beautiful, bathing and massaging visitors, singing and dancing, and, for male Tourists, providing company in bed. None of them seem unhappy in their work and they show no desire to escape. [...] Often male Tourists will sympathize with the plight of such Slaves, nobly reject their offer of free, no-holds-barred SEX, insist on assisting them to escape from the exploitative tyranny under which they have been existing, and then, having obviously done them a Good Turn, have free, no-holds-barred Sex before stranding them in the middle of nowhere to make their way thousands of miles back to their own COUNTRY."
- Drakengard 3: This trope gradually manifests in the form of Zero and her male Battle Harem, consisting of Dito, Decadus, Octa, and Cent. Prior to the main events of the game, the latter group existed to serve as bodyguards and concubines for the Intoners, a group of six goddesses with the power of Magic Music of which Zero is the eldest. As Zero kills her sisters in her plan to become the only living Intoner in existence, she recruits each sister's respective Disciple, all of whom who pledge their loyalty to her.
- Star Wars: The Old Republic: Downplayed in that it isn't possible to build a harem with any PC.note However, the male Sith Warrior is given a Twi'lek slave named Vette, complete with Shock Collar to ensure her compliance. Originally, while taking the collar off immediately would quickly get the Warrior on her good side and using it on her would quickly turn her against the Warrior, it was not impossible to have her fall in love with the Warrior even if he left the collar on her. Later patches removed this option, and Vette will now only get romantically entangled with a Warrior who takes off the collar... though she does keep it and hold onto it for personal reasons. Vette also understandably gets royally pissed off if the Warrior PC tries to get her sister Tivva to service him or their male crew members as a condition of buying Tivva's freedom.
- Mocked in this comic by artist Baalbuddy. A typical Isekai protagonist declares his hatred for slavery, but fears female rejection, so he goes to a slave-trader because he's a "nice guy" so that makes it okay. The slave trader offers him an expensive elf girl with powerful magic, but she is out of his price range, so he instead gives him a quartet of 4 female goblins with obvious personality flaws.
- Discussed Trope (although without the "harem" aspect) in Explanation Point's analysis of The Rising of the Shield Hero. He argues that the reason slavery has become so popular and enjoyable for many fans of isekai/light novel power fantasies is for two reasons. One, slaves are "blameless" and are thus free of the same flaws and evil that plagues the rest of humanity. And two, the trope presents a world in which the capitalist ideal works, whereas serving a "great" person also benefits the person doing the serving. However, he also notes that this only works because Naofumi himself is unrealistic; Naofumi never treats his slaves with contempt and never tries to take more than what he needs from them or others he has power over, which (he argues) is the case more often than not in Real Life.
"Raphtalia is capable of providing Naofumi with all the benefits of human companionship without any of what Naofumi would consider to be the 'pitfalls' of humanity. She's incapable of betrayal, deceit, lies. Why? Exactly because she's a slave, forced by magic to be perfectly subservient. This is Shield Hero's idea of the responsibility of the powerless to the powerful. They're intended to be tools, assisting those with power and influence in achieving their goal. [...] This hits on the capitalist ideal that Shield Hero's world is trying to present: that which benefits Naofumi benefits Raphtalia because Raphtalia serves Naofumi. In serving Naofumi, Raphtalia is, in turn, serving herself. Likewise, in serving himself, Naofumi is serving Raphtalia, and (inadvertently or not) he serves society at large. As I said before, Shield Hero argues that what's good for the individual is, ultimately, good for the collective, whether they intend it to be or not."
- Discussed Trope in the Terrible Writing Advice "Isekai" episode, when he discusses harems. He breaks character in shock when he reads that this is a popular trope in his script, and then lampshades the creepiness of the protagonist supporting slavery instead of heroically ending it.